Cooling and heating unit of air-cooled heat pump type

ABSTRACT

In discharging exhaust room air through a heat exchange coil, outside air is introduced into a case housing the heat exchange coil and the exhaust room air and outside air are mixed together within the case. The mixed air is discharged out-of-doors through the heat exchange coil. Thus the outside air supplied makes up for the shortage of the exhaust room air to be passed through the heat exchange coil for heat exchange.

United States Patent [1 1 Okuma et al.

COOLING AND HEATING UNIT OF AIR-COOL'ED HEAT PUMP TYPE Inventors: Yoshiro Okuma, Toyonaka; Keizo llnuzuka, Yokohama, both of Japan Nihon Netsugaku Kogyo Kabushiki Kaisha, Kitaku, Osaka, Japan Filed: Dec. 27, 1971 Appl. No.: 211,921

Assignee:

Foreign Application Priority Data Mar. 30, 1971 Japan 46-22964 US. Cl. 165/29, 62/324 Int. Cl F25b 24/00 Field of Search 165/29, 39; 62/324 References Cited UNITED STATES PATENTS 1/1934 Kerr,vJr. et aI. 62/324 [4 1 Jan. 15,1974

Primary ExaminerCharles Sukalo Attorney-Holman & Stern 5 7] ABSTRACT 2 Claims, 3 Drawing Figures PATENTEB JAM 5 i974 sum 1 [1F 2 COOLING AND HEATING UNIT 01F AIR-COOLED HEAT PUMP TYPE BACKGROUND OFTl-IEINVENTION The present invention relates to a cooling and heating unit of the air-cooled heat pump type, and more particularly to a cooling and heating unit of the heat pump type to be disposed in each room for conjoint use with a central air conditioner in which unit exhaust room air is passed through its heat exchange coil for heat exchange.

With a system wherein the air is conditioned to a suit-- able temperature by a central air conditioner and the conditioned air is further conditioned in respective rooms by cooling and heating units of the heat pump type disposed therein, the exhaust room air is utilized for the operation of the units. In operating such a system, it is not infrequently experienced that the amount of the exhaust air corresponding to that of the conditioned air supplied from the central air conditioner may possiblybe insufficient to operate the cooling and heating unit depending upon the conditions within the room. If it is attempted to increase the amount of conditioned air to be supplied to the room in order to avoid the shortage of the air supply, there arises a need to substantially step up the capacity of the central air conditioner, resulting in an increase in installation cost as well as in maintenance cost with a further disadvantage of a greater space needed forthe provision of ducts.

SUMMARY OF THE INVENTION An object of this invetion is to make up for the shortage of exhaust room air to be passed through and heatexchanged by the heat exchange coil of a cooling and heating unit by very simple means so as to permit the cooling and heating unit to operate with high efficiency.

In accordance with the present invention, an exhaust air outlet is formed in the wall of a building for discharging the exhaust room air which has passed through the heat exchange coil and an outside air intake is provided for a case which houses the heat exchange coil. The case is formed with an exhaust room air intake at its room side and has a blower disposed in front of the heat exchange 'coil for forcing the exhaust air into contact with the heat exchange coil, the exhaust room air intake being provided with a suitable damper serving also as a shutter. The damper functions to close the exhaust room air intake when the cooling and heating unit is brought out of operation and, upon the unit being initiated into operation, to open the exhaust room air intake to an adjustable extent so as to control the ratio of the outside air intake to the amount of the exhaust room air to be introduced into the case.

The outside air intake is of such size as to introduce into the case sufficient outside air to make up for the shortage of the exhaust room air to thereby permit the heat exchange coil to fully perform its function.

Thus, irrespective of whether the exhaust room air is sufficient or insufficient for heat exchange, the present invention enables the cooling and heating unit to operate with good efficiency by employing means of a very simple construction.

The present invention further permits a reduction in the amount of conditioned air to be supplied to the room, eliminating the need to employ a central air conditioner of an increased capacity, achieves reduction in the capacity of the ducts to thereby reduce the space required for the installation of the ducts, provides automated air conditioning all the year round, and serves to simplify the outdoor equipment. As a result, the invention ensures operation with improved economy and reduction in installation and maintenance costs.

Other objects and features of the invention will become more apparent from an optimum embodiment of a cooling and heating unit of the air-cooled heat pump type in accordance with this invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing an example of a central air conditioning system embodying this ivention;

FIG. 2 is a plan view in section showing the principal part of a cooling and heating unit in accordance with this invention; and

FIG. 3 is a sectional view taken along the line Ill-Ill in FIG. 2, the view looking in the direction of the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a central air conditioner 1 disposed at a suitable position as on the roof top of a building supplies conditioned air via ducting 2 to rooms 3 each of which is equipped with a cooling and heating unit 4 of the air-cooled heat pump type, whereby the room air is conditioned to a desired temperature and excess air is discharged from the room.

As shown in greater detail in FIG. 2, the unit 4 has a case 5 including a suitable number of compartments 6, 7, 8 and 9. The compartment 6 accommodates a heat exchange coil 10 serving as a condenser for cooling operation and an evaporator for heating; the compartment 8, a heat exchange coil 11 serving as an evaporator for cooling and a condenser for heating; and the compartment 9, a compressor 12 and a four-channel changeover valve 13. These devices are connected together by tubes 14 for a cooling medium by way of capillary tubes 15 and check valves 16, etc. The changeover valve 13 switches the channel of the cooling medium for cooling or heating operation as desired.

The compartment 8 has a room air circulation opening 18 equippedwith a filter 1.7 in front of the heat exchange coil 11 and means for forced air circulation such as a blower 19 positioned in rear of the heat exchange coil 11, with the arrangement being such that the room air is drawn in through the opening 18 for contact with the heat exchange coil 11 and is discharged into the room after heat exchange.

The compartment 7 is formed at its room side with an opening 21 equipped with a filter 20 for drawing in the exhaust room air. A blower 22 positioned at the boundary of the compartments 6 and 7 forces the exhaust room air into contact with the heat exchange coil 10 for heat exchange. Throughan exhaust outlet 23 of the compartment 6 and another exhaust outlet 25 formed in a wall 24 of the building, the exhaust room air is then discharged out-of-doors. To prevent the entry of the airborne dust while the unit 4 is out of operation, the exhaust outlet 23 is provided with a filter 26.

The compartment 7 has an outside air intake 29 communicating through a filter 28 with an outside air intake 27 formed in the wall 24. The opening 21 of the compartment 7 is equipped with a damper 30 serving also as a shutter which closes the opening 21 while the unit is out of operation and opens the opening 21 upon the initiation of operation of the unit to an adjustable extent in accordance with the shortage of the exhaust room air to be applied to the heat exchange coil for heat exchange.

Along the outer wall of the exhaust outlet and outside air intake 27, a wind breaker 31 may preferably be provided to protect the unit from the external pressure of strong wind, etc. Further the damper may be provided with a sound absorbing member to block the outside noise.

When the cooling and heating unit 4 is operated in the room 3 to which conditioned air is supplied from the central air conditioner l, the damper 30 opens to permit the blower 22 to force the exhaust room air into contact with the heat exchange coil 10 and discharge the same from the room. To make up for the shortage of air to be brought into contact with the heat exchange coil 10, the damper 30 is opened to a controlled extent to introduce outside air into the compartment 7 through the outside air intake 27 for admixture with the exhaust room air and the mixed air is then forced by the blower 22 to contact the heat'exchange coil 10. The air is thereafter discharged outside. Thus, in operating the cooling and heating unit of the air-cooled heat pump type with the exhaust room air, the shortage of the air with the supply of the exhaust room air is made up for by the introduction of outside air so as to satisfactorily adapt the unit to the conditions within the room for the greatest possible operation efficiency.

For a more efficient operation of the heat exchange coil 10 during heating operation, a heater may be installed in front of the coil 10 with a thermostat provided therefor for turning the heater on and off.

What is climed is:

1. A cooling and heating unit of the air-cooled heat pump type in which a first heat exchange coil for room air-conditioning serving as an evaporator for cooling and as a condenser for heating and a second heat exchange coil serving as a condenser for cooling and as an evaporator for heating are housed in independent cases; and room air supplied after pre-conditioning from a central air-conditioner is introduced into the case housing the first heat exchange coil, brought into contact with the first heat exchange coil and discharged indoors; and the second heat exhcange coil is brought into the case housing the second heat exchange coil into contact with excessive exhaust room air to be discharged outdooors, through said case comprising,

an outside air intake for introducing outside air into the case housing the second heat exchange coil,

a damper serving also as a shutter provided in an opening of said case for introducing exhaust room air, said damper closing said opening when said unit is brought out of operation and opening said opening when said unit is placed into operation, and a blower for mixing the exhaust room air with the outside air within said case and bringing the mixture into contact with said second heat exchange coil.

2. The cooling and heating unit as set forth in claim 1 wherein said damper is opened to an adjusted extent corresponding to the shortage of the exhaust room air to be brought into contact with said second heat exchange coil so as to control the amount of the outside air taken in. 

1. A cooling and heating unit of the air-cooled heat pump type in which a first heat exchange coil for room air-conditioning serving as an evaporator for cooling and as a condenser for heating and a second heat exchange coil serving as a condenser for cooling and as an evaporator for heating are housed in independent cases; and room air supplied after pre-conditioning from a central air-conditioner is introduced into the case housing the first heat exchange coil, brought into contact with the first heat exchange coil and discharged indoors; and the second heat exhcange coil is brought into the case housing the second heat exchange coil into contact with excessive exhaust room air to be discharged outdooors, through said case comprising, an outside air intake for introducing outside air into the case housing the second heat exchange coil, a damper serving also as a shutter provided in an opening of said case for introducing exhaust room air, said damper closing said opening when said unit is brought out of operation and opening said opening when said unit is placed into operation, and a blower for mixing the exhaust room air with the outside air within said case and bringing the mixture into contact with said second heat exchange coil.
 2. The cooling and heating unit as set forth in claim 1 wherein said damper is opened to an adjusted extent corresponding to the shortage of the exhaust room air to be brought into contact with said second heat exchange coil so as to control the amount of the outside air taken in. 